unsigned Cartridge::find_header(const uint8_t *data, unsigned size) const {
unsigned score_lo = score_header(data, size, 0x007fc0);
unsigned score_hi = score_header(data, size, 0x00ffc0);
unsigned score_ex = score_header(data, size, 0x40ffc0);
if(score_ex) score_ex += 4; //favor ExHiROM on images > 32mbits
if(score_lo >= score_hi && score_lo >= score_ex) {
return 0x007fc0;
} else if(score_hi >= score_ex) {
return 0x00ffc0;
} else {
return 0x40ffc0;
}
}
unsigned SuperFamicomCartridge::find_header(linput_t *li) {
unsigned score_lo = score_header(li, 0x007fc0);
unsigned score_hi = score_header(li, 0x00ffc0);
unsigned score_ex = score_header(li, 0x40ffc0);
if(score_ex) score_ex += 4; //favor ExHiROM on images > 32mbits
if(score_lo >= score_hi && score_lo >= score_ex) {
return 0x007fc0;
} else if(score_hi >= score_ex) {
return 0x00ffc0;
} else {
return 0x40ffc0;
}
}
/**
* Score a header.
*
* Give FLAC_HEADER_BASE_SCORE points to a frame for existing.
* If it has children, (subsequent frames of which the preceding CRC footer
* validates against this one,) then take the maximum score of the children,
* with a penalty of FLAC_HEADER_CHANGED_PENALTY applied for each change to
* bps, sample rate, channels, but not decorrelation mode, or blocksize,
* because it can change often.
**/
static int score_header(FLACParseContext *fpc, FLACHeaderMarker *header)
{
FLACHeaderMarker *child;
int dist = 0;
int child_score;
if (header->max_score != FLAC_HEADER_NOT_SCORED_YET)
return header->max_score;
header->max_score = FLAC_HEADER_BASE_SCORE;
/* Check and compute the children's scores. */
child = header->next;
for (dist = 0; dist < FLAC_MAX_SEQUENTIAL_HEADERS && child; dist++) {
/* Look at the child's frame header info and penalize suspicious
changes between the headers. */
if (header->link_penalty[dist] == FLAC_HEADER_NOT_PENALIZED_YET) {
header->link_penalty[dist] = check_header_mismatch(fpc, header,
child, AV_LOG_DEBUG);
}
child_score = score_header(fpc, child) - header->link_penalty[dist];
if (FLAC_HEADER_BASE_SCORE + child_score > header->max_score) {
/* Keep the child because the frame scoring is dynamic. */
header->best_child = child;
header->max_score = FLAC_HEADER_BASE_SCORE + child_score;
}
child = child->next;
}
return header->max_score;
}
static enum ssnes_mapper_type find_mapper_type(const uint8_t *data, size_t size)
{
// One 32KiB bank, has to be LoROM.
if (size < 0x10000)
return SSNES_MAPPER_LOROM;
unsigned score_lo = score_header(data, size, 0x7fc0);
unsigned score_hi = score_header(data, size, 0xffc0);
unsigned index = (score_lo > score_hi) ? 0x7fc0 : 0xffc0;
if (index == 0xffc0)
return SSNES_MAPPER_HIROM;
else
return SSNES_MAPPER_LOROM;
}
static void score_sequences(FLACParseContext *fpc)
{
FLACHeaderMarker *curr;
int best_score = FLAC_HEADER_NOT_SCORED_YET;
/* First pass to clear all old scores. */
for (curr = fpc->headers; curr; curr = curr->next)
curr->max_score = FLAC_HEADER_NOT_SCORED_YET;
/* Do a second pass to score them all. */
for (curr = fpc->headers; curr; curr = curr->next) {
if (score_header(fpc, curr) > best_score) {
fpc->best_header = curr;
best_score = curr->max_score;
}
}
}
/**
* Score a header.
*
* Give FLAC_HEADER_BASE_SCORE points to a frame for existing.
* If it has children, (subsequent frames of which the preceding CRC footer
* validates against this one,) then take the maximum score of the children,
* with a penalty of FLAC_HEADER_CHANGED_PENALTY applied for each change to
* bps, sample rate, channels, but not decorrelation mode, or blocksize,
* because it can change often.
**/
static int score_header(FLACParseContext *fpc, FLACHeaderMarker *header)
{
FLACHeaderMarker *child;
int dist = 0;
int child_score;
int base_score = FLAC_HEADER_BASE_SCORE;
if (header->max_score != FLAC_HEADER_NOT_SCORED_YET)
return header->max_score;
/* Modify the base score with changes from the last output header */
if (fpc->last_fi_valid) {
/* Silence the log since this will be repeated if selected */
base_score -= check_header_fi_mismatch(fpc, &fpc->last_fi, &header->fi,
AV_LOG_DEBUG);
}
header->max_score = base_score;
/* Check and compute the children's scores. */
child = header->next;
for (dist = 0; dist < FLAC_MAX_SEQUENTIAL_HEADERS && child; dist++) {
/* Look at the child's frame header info and penalize suspicious
changes between the headers. */
if (header->link_penalty[dist] == FLAC_HEADER_NOT_PENALIZED_YET) {
header->link_penalty[dist] = check_header_mismatch(fpc, header,
child, AV_LOG_DEBUG);
}
child_score = score_header(fpc, child) - header->link_penalty[dist];
if (FLAC_HEADER_BASE_SCORE + child_score > header->max_score) {
/* Keep the child because the frame scoring is dynamic. */
header->best_child = child;
header->max_score = base_score + child_score;
}
child = child->next;
}
return header->max_score;
}
